RSNA: Walking Staves Off Dementia

Action Points

Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

Explain that individuals without signs of dementia at baseline who walked six miles or more a week had preserved brain volume by MRI and a 50% decreased risk of Alzheimer's disease over 13 years of follow-up.

Note that individuals with mild cognitive impairment who walked at least five miles a week also had more preserved brain volume and less cognitive decline when compared to those who were sedentary in this longitudinal study.

CHICAGO -- Walking about six miles a week reduced the risk of developing Alzheimer's disease and slowed progression of mild cognitive impairment, researchers reported here.

Participants in a prospective cohort study who walked moderately had a 50% reduced risk of developing the disease over a 13-year period, according to Cyrus Raji, PhD, of the University of Pittsburgh, and colleagues.

Walking also reduced the loss of brain volume and slowed memory loss in patients who already had mild cognitive impairment (MCI), Raji said during a press briefing at the Radiological Society of North America meeting.

"In people with MCI, walking just five miles a week reduced brain atrophy and cognitive decline -- by more than 50%," Raji said.

To get their data, he and his colleagues turned to the Cardiovascular Health Study -- Cognition Study (CHS-CS), which began in 1989 with 1,479 patients. They looked at records of patients who had a brain MRI between 1992 and 1994.

A total of 426 patients had a follow-up MRI between 1998 and 1999. Of those, 299 were cognitively normal, 83 had mild cognitive impairment, and 44 had Alzheimer's.

At the start of the study, participants completed questionnaires about their exercise habits, and filled out follow-up questionnaires every three years. The amount of walking remained the same over the study, Raji said.

Patients were also given the Mini-Mental State Exam (MMSE) at various times throughout the study, with the final one five years after the second MRI scan.

The researchers found that among healthy adults, brain volume was preserved in those who walked at least six miles a week -- and it was preserved in key areas, including the prefrontal cortex and temporal cortex, which play a role in memory, Raji said.

Clinical exams and MMSE scores showed walking this distance was associated with a 50% decline in Alzheimer's risk over 13 years.

Those who already had cognitive impairment also benefited from walking. Those who tallied at least five miles a week had smaller mean losses in brain volume -- just one point on the MMSE over 10 years, compared with five points for those who were sedentary.

The relationship between walking and preserved brain volume persisted even after the analysis was adjusted to take into account other risk factors for dementia, including age, gender, and high blood pressure.

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